Back to the room.

As Sandy gets back up to the room she notices the curtains were suddenly open. You could now look straight into the room through the huge glass walls.

"Has somebody been in the room and is he still in there?" She thinks.

She just walks carefully and scared through the door. She sees nobody inside. She also has a look inside the bathroom but nobody was there too. Whoever was there must be gone by now she just walks towards the curtains of the glass wall to close them again.

But as she gets there she notices the curtains were completely gone. She was completely in view when somebody would walk by.